A continuous zoom lens arrangement can image MWIR and LWIR spectral bands to a common image plane. Such an exemplary optical system comprises eight infrared imaging lenses that all transmit over the wavelengths 3.5-11.0 microns and form a collocated image plane for the MWIR and LWIR spectral bands. The lens has six stationary lenses, and two lenses that move in an axial fashion. A cold stop inside the dewar can act as the aperture stop of the system and control the stray light from reaching the FPA. The pupil is reimaged from the cold stop to near the first lens of the system to minimize the size of the lens.
展开▼